#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.h>
#else
#define debug(...)
#endif
#define ft front
#define bk back
#define st first
#define nd second
#define ins insert
#define ers erase
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define bg begin
#define ed end
#define all(x) (x).bg(), (x).ed()
#define sz(x) (int)(x).size()
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
template<typename T> T gcd(T a, T b) { return (b == 0? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
#define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
#define FRN(i, n) for (int (i) = 0; (i) < (n); ++(i))
#define FSN(i, n) for (int (i) = (n) - 1; (i) >= 0; --(i))
#define EACH(i, x) for (auto &(i) : (x))
#define WHILE while
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
----------------------------------------------------------------
END OF TEMPLATE
----------------------------------------------------------------
Tran The Bao - ghostwriter
Training for VOI23 gold medal
----------------------------------------------------------------
DIT ME CHUYEN BAO LOC
----------------------------------------------------------------
*/
const int M = 1000000207;
const int base = 29;
const int N = 3e5 + 5;
int n, d[N];
str s;
int p[N], h[N], h1[N];
vpi v;
vi v1, v2;
map<int, bool> d1;
ll rs = 0;
int geth(const int &l, const int &r) { return (h[r] - 1LL * h[l - 1] * p[r - l + 1] % M + M) % M; }
int geth1(const int &l, const int &r) { return (h1[l] - 1LL * h1[r + 1] * p[r - l + 1] % M + M) % M; }
bool cmp(const pi &a, const pi &b) { return a.nd - a.st + 1 < b.nd - b.st + 1; }
int getpos(const int &x) { if (x > v1.bk()) return -1; int ans = lb(all(v1), x) - v1.bg(); return x == v1[ans]? ans : -1; }
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
// freopen(file".inp", "r", stdin);
// freopen(file".out", "w", stdout);
p[0] = 1;
FOR(i, 1, N - 1) p[i] = 1LL * p[i - 1] * base % M;
cin >> s;
n = sz(s);
s = "#" + s + "#";
FOR(i, 1, n) h[i] = (1LL * h[i - 1] * base % M + s[i] - 'a' + 1) % M;
FOS(i, n, 1) h1[i] = (1LL * h1[i + 1] * base % M + s[i] - 'a' + 1) % M;
FOR(i, 1, n) {
int l = 1, r = min(i - 1, n - i), ans = 0;
WHILE(l <= r) {
int mid = l + (r - l) / 2;
if (geth(i - mid, i + mid) == geth1(i - mid, i + mid)) {
ans = mid;
l = mid + 1;
}
else r = mid - 1;
}
l = i - ans;
r = i + ans;
int curh = geth(l, r);
v2.pb(curh);
WHILE(!d1[curh]) {
v.pb({l, r});
d1[curh] = 1;
++l;
--r;
if (l > r) break;
curh = geth(l, r);
}
}
FOR(i, 1, n - 1) {
if (s[i] != s[i + 1]) continue;
int l = 1, r = min(i - 1, n - i - 1), ans = 0;
WHILE(l <= r) {
int mid = l + (r - l) / 2;
if (geth(i - mid, i + 1 + mid) == geth1(i - mid, i + 1 + mid)) {
ans = mid;
l = mid + 1;
}
else r = mid - 1;
}
l = i - ans;
r = i + 1 + ans;
int curh = geth(l, r);
v2.pb(curh);
WHILE(!d1[curh]) {
v.pb({l, r});
d1[curh] = 1;
++l;
--r;
if (l > r) break;
curh = geth(l, r);
}
}
sort(all(v), cmp);
EACH(i, v) v1.pb(geth(i.st, i.nd));
sort(all(v1));
EACH(i, v2) ++d[getpos(i)];
FSN(i, sz(v)) {
int ln = v[i].st, rn = v[i].nd, len = rn - ln + 1;
int posh = getpos(geth(ln, rn));
rs = max(rs, 1LL * d[posh] * len);
if (ln + 1 <= rn - 1) d[getpos(geth(ln + 1, rn - 1))] += d[posh];
}
cout << rs;
return 0;
}
/*
abbabaaa
----------------------------------------------------------------
From Benq:
stuff you should look for
* int overflow, array bounds
* special cases (n=1?)
* do smth instead of nothing and stay organized
* WRITE STUFF DOWN
* DON'T GET STUCK ON ONE APPROACH
----------------------------------------------------------------
*/
